Oculocutaneous Albinism Type 1 Diagnosed by Genetic Study in a Newborn Infant / 대한주산의학회잡지

Oculocutaneous Albinism (OCA) is a heterogenous autosomal recessive disorder characterized by defective melanin biosynthesis. Physical findings including white scalp hair and depigmented skin of whole body in newborn infants are important clinical features of OCA 1. We report a newborn case of OCA 1 with two different TYR mutations, and gene defects of the baby revealed to be originated from both parents carriers of OCA.

A Case of Oculocutaneous Albinism Induced by Tyrosinase Mutation / 대한피부과학회지

Oculocutaneous albinism (OCA) is a group of inherited disorders of the melanin synthesizing system, and these are characterized by hypopigmentation of the hair, skin and eyes, with a normal number of melanocytes. The defect of melanin biosynthesis is caused by genetic mutation of such enzymes as tyrosinase (TYR), and tyrosinase-related protein (TYRP), which affect tyrosine convert to melanin pigment. There are at least four types of OCA from OCA1 to OCA4. The different types of OCA are caused by mutations in different genes. The most severe form, OCA1A, is distinguishable from other forms owing to a complete lack of melanin pigment throughout the patient's whole life. But among other types, except OCA1A, it is hard to identify the correct type according to only the clinical findings because their clinical phenotypes usually overlap. Therefore, molecular study is a useful tool for the typing and diagnosis of OCA. We experienced a case of a 10-month-old male toddler who has pale skin, straw-colored hair, nystagmus and visible choroidal vessels. Under the clinical impression of OCA, the correct subtyping was made on the basis of genetic analysis of the chromosomes and we found a new TYR gene frame-shift mutation.